$x_i$ | $P(x_i)$ | $x_i P(x_i)$ |
---|---|---|
$0$ | $4C_0 (\frac{2}{3})^4$ | $0$ |
$1$ | ${ }^{4} \mathrm{C}_{1}\left(\frac{2}{3}\right)^{3}\left(\frac{1}{3}\right)$ | ${ }^{4} \mathrm{C}_{1}\left(\frac{2}{3}\right)^{3}\left(\frac{1}{3}\right)$ |
$2$ | ${ }^{4} \mathrm{C}_{2}\left(\frac{2}{3}\right)^{2}\left(\frac{1}{3}\right)^{2}$ | $2\left({ }^{4} C_{2}\left(\frac{2}{3}\right)^{2}\left(\frac{1}{3}\right)^{2}\right)$ |
$3$ | ${ }^{4} \mathrm{C}_{3}\left(\frac{2}{3}\right)\left(\frac{1}{3}\right)^{3}$ | $3\left({ }^{4} \mathrm{C}_{3}\left(\frac{2}{3}\right)\left(\frac{1}{3}\right)^{3}\right)$ |
$4$ | ${ }^{4} \mathrm{C}_{4}\left(\frac{1}{3}\right)^{4}$ | $4\left({ }^{4} \mathrm{C}_{4}\left(\frac{1}{3}\right)^{4}\right)$ |